Readme.md

Reverse Polish Notation calculator

A simple implementation of a RPN (also known as postfix notation) calculator.

In a nutshell, this notation consists of operands followed by their operators.
As opposed to express an operation like this...

(3 + 4) * 7 - 1

...in reverse Polish notation it would look like this:

7 3 4 + * 1 -

It basically works like a stack in which you push operands until you find an
operator; given an arity n, you evaluate this operator with n numbers from
the stack, and substitute them for their result. Check out the Wikipedia
article to learn more about this notation.

Install

gem install rpn

Usage

Just require it in your Gemfile:

gem 'rpn'

Note: If you are not using Bundler, you should require 'rpn' manually.

Now you have to initialize a calculator. You can provide a custom n arity
(the number of operands that will get evaluated by each operator). Default
arity is 2. You can also provide the delimiter the parser will use (will be ' '
by default).